Accounting method for ultra mobile broadband access network

ABSTRACT

An accounting method for an ultra mobile broadband access network, wherein the method includes: S 402 , when a data binding point or access gateway AGW triggers a session reference network controller SRNC to initiate the paging to an access terminal AT, the SRNC sends an inter-ANRI signaling paging message to each evolved base station eBS in the paging area of the AT; S 404 , corresponding to a request from the SRNC, each eBS in the paging area of the AT performs the paging to the AT; S 406 , the eBS successfully paged an AT establishes the route between the eBS and the AT, creates the Air Link Record for the AT, and sends the accounting request (start) message related to the AT to the AGW serving the AT; and S 408 , after receiving the accounting request message, the AGW sends an accounting response message to the eBS successfully paged an AT to confirm that the AGW has received the accounting request message.

REFERENCE TO RELATED APPLICATIONS

This application is a national stage application of PCT Application No.PCT/CN/2007/003778 filed on Dec. 25, 2007. PCT Application No.PCT/CN/2007/003778 filed on Dec. 25, 2007 claims the benefit of ChinesePatent Application No. 200710153029.3 filed on Sep. 18, 2007 thedisclosure of which is considered part of (and is incorporated byreference in) the disclosure of this application.

FIELD OF THE INVENTION

The present invention relates to communication field, in particular toan accounting method for ultra mobile broadband access network in pagingprocess.

BACKGROUND OF THE INVENTION

The Ultra mobile broadband (UMB) technology is a new technologydeveloped from the CDMA 2000 access technology. Many technologies of theUMB air interface can substantially improve the performance of the CDMA2000 access technology network and establish an essential base forproviding more wireless multimedia service with higher-requirements tousers.

In order to support the UMB air interface technology, related network isalso under a new evolvement. FIG. 1 shows the network structuresupporting the access network of UMB technology in the art, wherein,

The access gateway (AGW) provides the “point of IP attachment point” tothe packet data network for an access terminal (AT). Thus, the AGWactually is the first jump router for the AT.

An evolved base station (eBS) is the logic entity capable ofcommunicating with an AT on the wireless carrier. For each AT beingserved, the eBS comprises an access network route instance (ANRI). Foreach AT, the eBS can play none or more of the following roles: forwardlink serving eBS (FLSE), reverse link serving eBS (RLSE) and dataattachment point (DAP).

The DAP is the bearer-plane point-of-contact for the AT to the AGW forforward-link data. The AGW sends the data and signaling relating to theAT to the DAP. The reverse link data from the AT can either betransmitted to the AGW via the DAP or directly transmitted to the AGW bythe RLSE.

The DAP can be relocated to a different eBS during the lifetime of thepacket data session based on several factors, such as performanceconsiderations. An example may be to move the DAP when the eBS hostingthe DAP is no longer a Route Set member

A session reference network controller (SRNC) is responsible formaintaining the session reference with the AT. The SRNC is alsoresponsible for supporting idle state management of the AT, andproviding paging control functions when the AT is in the idle state. Foreach AT being supported, the SRNC contains a session anchor ANRI.

It is noted that the SRNC can be implemented in various ways, such asbeing a standalone entity or being collocated in an eBS or in an AGW. Ifthe SRNC is collocated with the eBS, then both of them can share oneANRI.

In the network structure as shown in FIG. 1, reference point U1 is usedto carry the control plane and bearer plane information between the eBSand the AGW; reference point U2 is used to carry the control planeinformation between the SRNC and the eBS; reference point U3 is used tocarry the control plane and bearer plane information between two eBSs;reference point U4 is used to carry the control plane informationbetween SRNCs; and reference point U6 is used to carry the control planeinformation between the SRNC and the AGW.

At the same time, an accounting is a basic function required by awireless communication network. The access network supporting the UMBshould also have such a function. The accounting principle of the UMBnetwork is that the eBS sends the accounting information of wirelessresources to the AGW, and the AGW forwards the information to theAuthentication Authorization Accounting (AAA) unit of the core networkso as to generate, in a unified way, user accounting records for users.

Current access network technology already contains accounting functionin some aspects, for example, when a UMB session is established or whenan eBS is removed from the Route Set of a certain AT, the eBS sends therelated accounting information to the AGW. However, some aspects areignored in the art. That is to say, there is no accounting informationinteraction in the following processes or application.

As shown in FIG. 2, there is no accounting function for the currentprocess of the eBS paging the AT triggered due to the AGW having data tobe transmitted to the idle AT. As shown in FIG. 2, the current processof the eBS paging the AT triggered due to the AGW having data to betransmitted to the idle AT comprises the following steps:

S202, the connection between the AT and the FLSE has been closed; theAT, the SRNC and the eBS4 (DAP) are all in idle state; the eBS4 (DAP)can perform flow control to trigger the AGW to buffer data.

S204, when the data or data notification of the AT is received from theAGW, the eBS4 (DAP) is triggered to send a paging.

S206, the eBS4 (DAP) sends an inter-ANSI signaling (IAS)—paging requestmessage to the SRNC, wherein the message contains paging priority, flowcontrol status at the AGW, and a flag identifying that the paging areais unknown and needs to be temporarily acknowledged. The eBS4 (DAP)initiates a timer Tpgack_ias and waits for an IAS-Paging Request Ackmessage. At the same time, the eBS4 (DAP) also initiates a timerTpgreg-ias and waits for receiving an IP tunnel (IPT)-notificationmessage.

S208, upon receipt of the IAS-Paging Request message, the SRNC sends anIAS-Paging Request Ack to the eBS4 (DAP). Upon receipt of the IAS-PagingRequest Ack, the eBS4 (DAP) stops the timer Tpgack-ias. If the eBS4(DAP) receives the subsequent data and if the timer Tpgreg-ias does notexpire, then the eBS4 (DAP) will stop trying to send other IAS-PagingRequest message to the SRNC.

S210, the SRNC determines the paging area and sends the IAS-pagingmessage to each eBS in paging area of the AT. This process assumes thateBS1, eBS2, and eBS3 are all in the paging area. The IAS-Page messagecontains “Local Fanout Required” set to ‘0’ for no local fanout,implying no IAS-Page ACK message is required. the IAS-Paging messagealso contains the information on the time for initiating the pagingprocedure over the air and the priority of the paging request.

S212, eBS1, eBS2 and eBS3 page the AT via a specified channel and time.

S214, the call flow assumes that the AT has received the page sent byeBS1, and responds to the page by performing access procedure, i.e., theAT sends a RouteOpenRequest message to eBS1 to open a route with eBS1.

S216, upon receipt of the RouteOpenRequest message, eBS1 sends theIAS-Session Information Request message with a flag indicating access tothe SRNC to request a copy of the session, and at the same time, eBS1starts a timer Tsir-ias. Upon receipt of the IAS-Session InformationRequest message with a flag indicating access to the SRNC, the SRNCstops the timer Tpgreg-ias.

S218, the SRNC sends the IAS-Session Information Response message toeBS1, which contains session information and the access networkidentifier (ANID) of eBS4 (the DAP of the AT). eBS1 stops the timerTsir-ias after having received the IAS-Session Information Responsemessage.

S220, eBS1 sends a RouteOpenAccept message to the AT, so as to finishthe establishment of the route to the AT.

S222, eBS1 completes Key Exchange procedure with the AT. This step canbe performed in parallel with step S220.

S224, the AT updates the RouteMap with eBS1 and the SRNC.

After step S220 wherein RouteOpenAccept message has been sent to the AT,eBS1 notifies all access network route instances (ANRIs) in the RouteSet and eBS4 (the previous DAP of the AT) that it has become the FLSE ofthe AT.

S226, eBS1 sends the IPT-Notification message to the SRNC to indicatethat eBS1 has become a FLSE, and at the same time, eBS1 starts a timerTnot-ipt.

S228, upon receipt of the IPT-Notification message, the SRNC sends anIPT-Notification ACK message to eBS1. eBS1 stops the timer Tnot-iptafter receiving the IPT-Notification ACK message.

S230, according to the ANID of eBS1, eBS1 sends the IPT-Notificationmessage to eBS4 to indicate that eBS1 has become an FLSE, and at thesame time, eBS1 starts the timer Tnot-ipt.

S232, upon receipt of the IPT-Notification message, eBS4 sends theIPT-Notification ACK message to eBS1, and at the same time, eBS4 stopsthe timer Tpgreg-ias and enters into a connecting status. eBS1 stops thetimer Tnot-ipt after having received the IPT-Notification ACK message.

S234, if the AGW has no buffer data or eBS4 (DAP) has data for the AT,the data of eBS4 (DAP) will be forwarded to the AT through eBS1 whichcurrently is the FLSE.

S236, the eBS1, which currently is the FLSE, becomes the DAP of the AT.This step can occur any time after step S220.

S238, the data from the AGW is forwarded to eBS1 which has become theDAP.

As shown in FIG. 3, there is no accounting function for the currentprocess for paging an AT initiated by the SRNC as a data binding point.As shown in FIG. 3, the current process for paging an AT initiated bythe SRNC functioning as a data binding point comprises the followingsteps:

S302, the connection between the AT and FLSE has been closed. Both theAT and SRNC are in idle state. The SRNC becomes the current DAP throughmoving the binding of the proxy mobile IP (PMIP) tunnel from theoriginal DAP to the SRNC, and at the same time, the SRNC requests theAGW to buffer data. The original DAP has released all the resourcesallocated to the AT.

S304, the SRNC is triggered to request paging of the AT when the SRNCreceives the data notification of the AT from the AGW.

S306, the SRNC sends the IAS-Paging message to each eBS in paging areaof the AT. In this flow, it is assumed that all eBS1, eBS2, and eBS3 arein the paging area. The IAS-Paging message contains a reason informationunit with a value of “normal operation”, a paging control recordinformation unit for indicating paging priority and whether anacknowledgement is required, and an information unit containing therecord of the session status information for the time point when the airinterface initiates the paging flow. The SRNC starts one timerTpgreg-ias for each paging request message sent.

S308, eBS1, eBS2, and eBS3 page the AT via a specified channel and time.

S310, the call flow assumes that the AT has received the page sent byeBS1, and responds to the page by performing access procedure, i.e., theAT sends a RouteOpenRequest message to eBS1 to open a route with eBS1

S312, upon receipt of the RouteOpenReques message, eBS1 sends theIAS-Session Information Request message with a flag indicating access tothe SRNC to request a copy of the session, and at the same time, eBS1starts the timer Tsir-ias. Upon receipt of the IAS-Session InformationRequest message with a flag indicating access to the SRNC, the SRNCstops the timer Tpgreg-ias.

S314, the SRNC sends the IAS-Session Information ACK message to eBS1,which contains session information and the ANID of the DAP. eBS1 stopsthe timer Tsir-ias after having received the IAS-Session InformationACK.

S316, eBS1 sends a RouteOpenAccept message to the AT, and thus theestablishment of the route to the AT has finished.

S318, eBS1 completes Key Exchange procedure with the AT. This step canbe performed in parallel with step S320.

S320, the AT updates the RouteMap with eBS1 and the SRNC.

S322, eBS1 sends the IPT-Notification message to the SRNC to indicatethat eBS1 has become an FLSE according to the ANID of the DAP (i.e., theANID of the SRNC), and at the same time, eBS1 starts the timer Tnot-ipt.

S324, upon receipt of the IPT-Notification message, the SRNC sends anIPT-Notification ACK message to eBS1, and at the same time, the DAPstops the timer Tpgreg-ias and enters into a connection status. eBS1stops the timer Tnot-ipt after receiving the IPT-Notification ACKmessage.

AN-initiated DAP selection mode, eBS1/FLSE determines to assume the DAProle, and establishes a PMIP binding with the AGW so that bearer datacan be conveyed to the AT. This step can occur anytime after step S314in AN-initiated DAP selection mode, or after step S316 in AT-assistedDAP handoff mode

S326, if the AT is configured to employ the “DAP switch aided by AT”mode, the AT sends a DAPMoveRequest message to eBS1 to trigger theestablishment of the initial PMIP tunnel with the AGW.

S328, for the “AN-initiated DAP selection” mode, eBS1 updates the PMIPbinding with the AGW through sending a PMIP-Registration Request messageto the AGW. eBS1 starts the timer Trrq-pmip.

S330, the AGW sends a PMIP-Registration Response having a tunnellifetime to eBS1 to confirm the binding update. The target DAP stops thetimer Trrq-pmip.

S332, if the AT has sent the DAPMoveRequest message in S326, eBS1 sendsa DAP Assignment message indicating that the establishment of the PMIPtunnel has been finished.

S334, eBS1/DAP sends the IPT-Notification message to the SRNC and startsthe timer Tnot-ipt. This message contains the information indicatingthat eBS1 is the current DAP, and the timestamp of eBS1 for updating thePMIP tunnel with the AGW.

S336, the SRNC sends the IPT-Notification ACK message. eBS1/DAP stopsthe timer Tnot-ipt.

S338, the data from the AGW is forwarded to eBS1 which has become theDAP.

Based on the above description, the flows mentioned above do nottransfer any accounting related information to the AGW, thus these flowsare short of function supporting accounting, which is a severelimitation to the real network and is a substantial impairment tooperators' benefits.

SUMMARY OF THE INVENTION

In view of one or more of above problems, the present invention providesan accounting method for the ultra mobile broadband access network.

The accounting method for ultra mobile broadband access networkaccording to embodiments of the present invention comprises thefollowing steps: S402, when a data binding point or access gateway AGWtriggers a SRNC to initiate the paging to an AT, the SRNC sends aninter-ANRI signaling paging message to each evolved base station eBS inthe paging area of the AT; S404, corresponding to a request from theSRNC, each eBS in the paging area of the AT performs the paging to theAT; S406, the eBS successfully paged an AT establishes the route betweenthe eBS and the AT, creates the Air Link Record of the AT, and sends theaccounting request (start) message related to the AT to the AGW servingthe AT, and indicates the air link having been opened; and S408, afterreceiving the accounting request message, the AGW sends an accountingresponse message to the eBS successfully paged an AT.

Wherein, while sending the accounting request message to the AGW, theeBS successfully paged an AT starts the timer of specified time lengthso as to resend accounting request message to the AGW in case that noaccounting response message is received in the specified time length.

Wherein, the eBS successfully paged an AT records the information of thewireless resources occupied by related access terminals through creatingthe Air Link Record for access terminals, and incorporates accountingstart information into the accounting request message being sent to theAGW so as to indicate that the air link has been opened.

The present invention improves the accounting function for an accessnetwork supporting the UMB technology so as to improve the accountingfunction of the entire network which is critical to both operators andusers.

BRIEF DESCRIPTION OF THE DRAWINGS

The Drawings are provided for a further understanding of the presentinvention and form a part of the specification, which are used toexplain the present invention with embodiments of the present inventionrather than unduly limit the present invention, wherein,

FIG. 1 is a schematic view of the network structure of the UMB accessnetwork in the art;

FIG. 2 is a schematic flow chart showing the process of paging an accessterminal in the art, which is initiated by the eBS as an AGW triggereddata binding point;

FIG. 3 is a schematic flow chart showing the process of paging an accessterminal in the art, which is initiated by the SRNC as a data bindingpoint;

FIG. 4 is a schematic flow chart showing the accounting method for theultra mobile broadband access network according to the embodiments ofthe present invention;

FIG. 5 is a schematic flow chart showing the process of paging an accessterminal, which is initiated by the eBS as a data binding point, whichincludes the process shown in FIG. 4; and

FIG. 6 is a schematic flow chart showing the process of paging an accessterminal, which is initiated by the SRNC as the data binding point,which includes the process shown in FIG. 4.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The concrete embodiments of the present invention will be described indetail in connection with the drawings.

Reference is made to FIG. 4, which shows the accounting method for theultra mobile broadband access network according to the embodiments ofthe present invention. As shown in FIG. 4, the accounting methodcomprises the following steps: S402, when a data binding point or accessgateway AGW triggers a session reference network controller SRNC toinitiate the paging to an access terminal AT, the SRNC sends aninter-ANRI signaling paging message to each evolved base station eBS inthe paging area of the AT; S404, corresponding to a request from theSRNC, each eBS in the paging area of the AT performs the paging to theAT; S406, the eBS successfully paged an AT establishes the route betweenthe eBS and the AT, creates the Air Link Record for the AT, and sendsthe accounting request (start) message related to the AT to the AGWserving the AT; and S408, after receiving the accounting requestmessage, the AGW sends an accounting response message to the eBSsuccessfully paged an AT, to confirm that the AGW has received theaccounting request message.

Wherein, when the eBS successfully paged an AT sends the accountingrequest message to the AGW, the eBS starts the timer of specified timelength at the same time so as to resend accounting request message tothe AGW in case that no accounting response message is received in thespecified time length.

Wherein, the eBS successfully paged an AT records the information of thewireless resources occupied by related access terminals through creatingAir Link Record for access terminals, and incorporates accounting startinformation into the accounting request message being sent to the AGW soas to indicate that the air link has been opened

Reference is made to FIG. 5, which explains the process of paging anaccess terminal, wherein the eBS as the data binding point triggers theSRNC to initiate the process, and comprises the process shown in FIG. 4.As shown in FIG. 5, the process comprises the following steps:

S502, the connection between an AT and an FLSE has been closed. The AT,SRNC and eBS4 (DAP) are all in idle stage. eBS4 (DAP) can perform flowcontrol to trigger the AGW to buffer data.

S504, when receiving the data or data notification of the AT, eBS4 (DAP)is triggered to request paging of the AT.

S506, eBS4 (DAP) sends the IAS-Paging Request message to the SRNC withthe priority of the page, the status of flow control at the AGW, and aflag indicating the paging area is unknown and needed to be temporarilyacknowledged. eBS4 (DAP) starts a timer Tpgack_ias and waits for anIAS-Paging Request ACK message, and at the same time, eBS4 (DAP) alsostarts a timer Tpgreg-ias, and waits for receiving an IPT-Notificationmessage.

S508, Upon receipt of the IAS-Paging Request message, the SRNC respondswith an IAS-Paging Request ACK message to eBS4 (DAP). Upon receipt ofthe IAS-Paging Request ACK, eBS4 (DAP) stops the timer Tpgack-ias. IfeBS4 (DAP) receives the subsequent data, and the timer Tpgreg-ias doesnot expire, then eBS4 (DAP) will stop trying to send other IAS-PagingRequest message to the SRNC.

S510, the SRNC determines the paging area and sends the IAS-Pagingmessage to each eBS in paging area of the AT. This process assumes thateBS1, eBS2, and eBS3 are all in the paging area. The IAS-Page messagecontains “Local Fanout Required” set to ‘0’ for no local fanout,implying no IAS-Page ACK message is required. the IAS-Paging messagealso contains the information on the time for initiating the pagingprocedure over the air and the priority of the paging request.

S512, eBS1, eBS2 and eBS3 page the AT via a specified channel and time.

S514, the call flow assumes that the AT has received the paging sent byeBS1, and responds to the paging by performing access process, i.e., theAT sends a RouteOpenRequest message to eBS1 to open a route with eBS1.

S516, upon receipt of the route RouteOpenRequest message, eBS1 sends theIAS-Session Information Request message with a flag indicating access tothe SRNC to request a copy of the session, at the same time, eBS1 startsthe timer Tsir-ias. Upon receipt of the IAS-Session Information Requestmessage with a flag indicating access to the SRNC, the SRNC stops thetimer Tpgreg-ias.

S518, the SRNC sends the IAS-Session Information Response message toeBS1, which contains session information and the ANID of eBS4 (the DAPof the AT). eBS1 stops the timer Tsir-ias after having received theIAS-Session Information Response

S520, eBS1 sends a RouteOpenAccept message to the AT, so as to completethe route establishment with the AT.

S522, eBS1 completes Key Exchange procedure with the AT. This step canoccur in parallel with step S520.

S524, the AT updates the RouteMap with eBS1 and SRNC.

S526, eBS1 creates an Air Link Record for the AT and sends theaccounting request (start) message to the AGW. eBS1 starts a timer Tacu.

S528, the AGW sends the accounting response message to eBS1, and eBS1stops the timer Tacu after having received the message.

After having sent the RouteOpenAccept message to the AT in step S520,eBS1 notifies all the ANRI and eBS1 (the previous DAP of the AT) in theRoute Set that it has become the FLSE of the AT.

S530, eBS1 sends the IPT-Notification message to the SRNC to indicatethat eBS1 has become the FLSE. At the same time, eBS1 starts a timerTnot-ipt.

S532, upon receipt of the IPT-Notification message, the SRNC respondswith an IPT-Notification ACK message to eBS1. eBS1 stops the timerTnot-ipt after receiving the IPT-Notification ACK message.

S534, according to the ANID of eBS4, eBS1 sends the IPT-Notificationmessage to eBS4 to indicate that eBS1 has become the FLSE. At the sametime, eBS1 starts the timer Tnot-ipt.

S536, upon receipt of the IPT-Notification message, eBS4 responds withan IPT-Notification ACK message to eBS1. eBS1 stops the timer Tnot-iptafter receiving the IPT-Notification ACK message.

S538, if the AGW has no buffer data or eBS4 (DAP) has data for the AT,the data of eBS4 (DAP) will be forwarded to the AT through eBS1 which iscurrently the FLSE.

S540, the eBS1, which is currently the FLSE, becomes the DAP of the AT.This step can occur any time after step S520.

S542, the data from the AGW is forwarded to eBS1 which has become theDAP.

Reference is made to FIG. 6, which explains the process of paging anaccess terminal, wherein the AGW triggers the SRNC as the data bindingpoint to initiate the process comprising the process shown in FIG. 4. Asshown in FIG. 6, the process comprises the following steps:

S602, the connection between an AT and FLSE has been closed. Both the ATand SRNC are in idle state. The SRNC becomes the current DAP throughremoving the binding of the PMIP from the original DAP to the SRNC, andat the same time, the SRNC requests the AGW to buffer data. The originalDAP has released all the resources allocated to the AT.

S604, the SRNC is triggered to request paging of the AT when receivingthe data notification of the AT from the AGW.

S606, the SRNC sends the IAS-Paging message to each eBS in paging areaof the AT. In this flow, it is assumed that all eBS1, eBS2 and eBS3 arein the paging area. The IAS-Paging message contains a reason informationunit whose value is “normal operation”, a paging control recordinformation unit indicating paging priority and whether acknowledgementis required, and an information unit containing the record of thesession status information for the time when the air interface initiatesthe paging flow. The SRNC starts one timer Tpgreg-ias for each pagingrequest message sent.

S608, eBS1, eBS2 and eBS3 page the AT via a specified channel and time.

S610, the process assumes that the AT has received the paging sent byeBS1, and responds to the paging by performing access process, i.e., theAT sends a RouteOpenRequest message to eBS1 to open a route with eBS1.

S612, upon receipt of the RouteOpenRequest message, eBS1 sends theIAS-Session Information Request message with a flag indicating access tothe SRNC to request a copy of the session, and at the same time, eBS1starts the timer Tsir-ias. Upon receipt of the IAS-Session InformationRequest message with a flag indicating access to the SRNC, the SRNCstops the timer Tpgreg-ias.

S614, the SRNC sends the IAS-Session Information Response message toeBS1, which contains session information and the ANID of the DAP. eBS1stops the timer Tsir-ias after having received the IAS-SessionInformation Response.

S616, eBS1 sends a RouteOpenAccept message to the AT, so as to completethe route establishment with the AT.

S618, eBS1 completes Key Exchange procedure with the AT. This step canoccur in parallel with step S620.

S620, the AT updates the RouteMap with eBS1 and SRNC.

S622, eBS1 creates an Air Link Record for the AT and sends theaccounting request (start) message to the AGW. eBS1 starts a timer Tacu.

S624, the AGW sends the accounting response message to eBS1 which stopsthe timer Tacu after having received the message.

S626, eBS1 sends the IPT-Notification message to the SRNC to indicatethat eBS1 has become an FLSE according to the ANID of the DAP (i.e., theANID of the SRNC), and at the same time, eBS1 starts a timer Tnot-ipt.

S628, upon receipt of IPT-Notification message, the SRNC responds withan IPT-Notification ACK message to eBS1, and at the same time, the DAPstops timer the Tpgreg-ias and enters into connection status. eBS1 stopsthe timer Tnot-ipt after receiving the IPT-Notification ACK message.

AN-Initiated DAP selection mode, eBS1/FLSE determines to assume the DAProle, and establishes a PMIP binding with the AGW so that bearer datacan be conveyed to the AT. This step can occur anytime after step S614in AN-initiated DAP selection mode, or after step S616 in AT-assistedDAP handoff mode.

S630, if the AT is configured to employ the “DAP switch aided by AT”mode, the AT sends a DAPMoveRequest message to eBS1 to trigger theestablishment of the initial PMIP tunnel with the AGW.

S632, for the “AN-initiated DAP selection” mode, eBS1 updates the PMIPbinding with the AGW through sending a PMIP-Registration Request messageto the AGW. eBS1 starts a timer Trrq-pmip.

S634, the AGW sends the PMIP-Registration Response having tunnellifetime to eBS1 to confirm the attachment update. The target DAP stopsthe timer Trrq-pmip.

S636, if the AT sent the DAPMoveRequest t message in S630, eBS1 sends aDAP Assignment message indicating that the establishment of PMIP hasbeen finished.

S638, eBS1/DAP sends the IPT-Notification message to the SRNC and startsa timer Tnot-ipt. The message contains the information indicating thatthe eBS1 is the current DAP and the timestamp for eBS1 updating the PMIPtunnel with the AGW.

S640, the SRNC sends the IPT-Notification ACK message. eBS1/DAP stopsthe timer Tnot-ipt.

S642, the data from the AGW is forwarded to eBS1 which has become theDAP.

Due to the importance of the accounting information, in order to ensurethat the AGW can accurately receive the accounting information from theeBS, the eBS sets the timer Tacu upon sending the accounting informationto the AGW. Wherein, the time length of the timer Tacu can be flexiblyconfigured. If no accounting response message is received from the AGWbefore the timer expires, the eBS resends the accounting requestmessage. The eBS will stop sending the accounting information if noaccounting response message is received from the AGW after repeating theprocess several times (the number of times of the repetition can beconfigured in advance). The timer can be used not only in the flow ofthe present invention but also in any other flow relating to two piecesof accounting information.

Based on the above description, with respect to the fact that there isno accounting process or information relating to the UMB flow in thecurrent UMB access network technology, the present invention provides anaccounting information interactive process added to the AT paging flow,so as to improve the technology flow and the accounting function in theUMB access network, which is of essence in real network.

Above description is to illustrate the embodiments of the presentinvention but not to limit the present invention. Various alterationsand changes to the present invention are apparent to those skilled inthe art. The scope defined in the claims shall comprise anymodification, equivalent substitution and improvement in the spirit andprinciple of the present invention.

1. An accounting method for ultra mobile broadband access network,comprising the following steps, S402, sending, by a session referencenetwork controller (SRNC), an inter access network route instance (ANRI)signaling paging message to each evolved base station (eBS) in a pagingarea of an access terminal (AT), when a data binding point or an accessgateway (AGW) triggers the SRNC to initiate a paging to the AT; S404,performing, by each eBS in the paging area of the AT, the paging to theAT corresponding to a request from the SRNC; S406, establishing, by theeBS successfully paged the AT, a route with the AT, and sending, by theeBS successfully paged the AT, an accounting request message related tothe AT to the AGW serving the AT; and S408, upon receipt of theaccounting request message, the AGW sending an accounting responsemessage to the eBS successfully paged the AT so as to confirm that theaccounting request message has been received.
 2. The accounting methodaccording to claim 1, wherein the eBS successfully paged the AT starts atimer of a prescribed time length while sending the accounting requestmessage to the AGW, so as to resend the accounting request message tothe AGW in case that the accounting response message is not receivedwithin the prescribed time length.
 3. The accounting method according toclaim 2, wherein the eBS successfully paged the AT records theinformation of the wireless resources occupied by the AT throughcreating an Air Link Record for the AT.
 4. The accounting methodaccording to claim 3, wherein the eBS successfully paged the AT createsthe Air Link Record for the AT, and incorporates accounting start fieldinto the accounting request message to be sent to the AGW so as toindicate that the air link has been created.